Some of New Zealand's best loved species of birds have vanished from parts of the country - wiped out it appears by changing land use.
The 2007 edition of the Atlas of Bird Distribution shows some areas on the map are now known as "blank spots" for some bird species.
Professor Richard Holdaway, president of the New Zealand Ornithological Society, said that since the last edition of the atlas in 1985 there had been a noticeable decline in birds in certain areas, especially the Waikato.
"The area has the clearest gap of no birds. The place may be clean and tidy but it's not necessarily good for the birds.
"Very few can survive on straight green grass and in pine trees. They need the wild bits."
Birds like the morepork, which were well-distributed in 1985, are scarce in the Waikato and almost absent in the Hauraki Plains.
Hedge sparrows, pipits, redpolls, tuis, bellbirds and grey warblers are also now uncommon.
When the landscape was more varied 20 years ago they could be found throughout the area, Professor Holdaway said.
But sparrows, darlings, magpies, blackbirds and skylarks are still widespread.
"Think of a red wine stain on a white tablecloth; that stain is the Waikato area and its lack of birds," he said.
Researchers found Canterbury and Southland also had a decline in certain species, probably due to the expansion of agriculture.
And Marlborough has seen a major decline in birds because of grape vines being planted. Professor Holdaway said finches could survive on grapes but few other species could.
Some species, though, had spread over larger areas. The spurwing plover is now spread throughout the North Island, when in 1985 it remained only in certain parts.
And the welcome swallow now spans the entire country.
"What used to just be a few dots here and there are now everywhere," Professor Holdaway said.
Adult birds generally died off if not in their right habitat but babies could relocate, he said.
The eastern rosella, an Australian parrot considered a pest, has established itself from Northland down to Taranaki and from Wellington upwards. By the next edition of the atlas, they are expected to be spread throughout the North Island.
The blackbird is the most widespread bird in New Zealand and Foxton beach has the most diverse assembly of birds in the country, probably because of overseas species resting there.
The research took five years and involved about 800 observers who were allocated 10km by 10km zones, covering about 96 per cent of the country.
They recorded the species they saw, and breeding distribution and habitats, but not the number of birds seen.
Some species were not seen at all.
The next edition of the atlas is not expected for another 20 years.